3877665661 has 8 divisors (see below), whose sum is σ = 4025868120. Its totient is φ = 3730429248.

The previous prime is 3877665641. The next prime is 3877665683. The reversal of 3877665661 is 1665667783.

It can be written as a sum of positive squares in 4 ways, for example, as 351562500 + 3526103161 = 18750^2 + 59381^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 3877665661 - 2²⁷ = 3743447933 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3877665641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 233326 + ... + 249391.

It is an arithmetic number, because the mean of its divisors is an integer number (503233515).

Almost surely, 2^3877665661 is an apocalyptic number.

It is an amenable number.

3877665661 is a deficient number, since it is larger than the sum of its proper divisors (148202459).

3877665661 is a wasteful number, since it uses less digits than its factorization.

3877665661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 483023.

The product of its digits is 7620480, while the sum is 55.

The square root of 3877665661 is about 62270.9054133630. The cubic root of 3877665661 is about 1571.0504094845.

The spelling of 3877665661 in words is "three billion, eight hundred seventy-seven million, six hundred sixty-five thousand, six hundred sixty-one".